Returning from the university in Mexico to California around 1850, Don Francisco Delfino finds his native land in the hands of unscrupulous Americans, his family estate in shambles, and his loved ones living in fear. Anger drives Francisco to stampede a herd of cattle he is delivering to Peter Harkness, the crooked land commissioner, and still obtain his money--thus earning him the name "El Puma." Don Francisco and others start making Robin Hood-type bandit raids, one of which leads to Francisco's rescue by Sheriff David Howard, their subsequent friendship, and David's love for Francisco's sister, Dolores. Finally avenging his father's murder by killing Harkness, Francisco must leave not only California but also his faithful love, Rosita, and his sometime sweetheart, Lupe; however, David gives him a head start, and Rosita promises to meet him in Mexico.

This film's working title was Adiós . Although The Lash was not the first feature film in Vitascope, a widescreen process developed by Warner Bros., according to the LAT review, it was the first complete Vitascope feature to be exhibited in Los Angeles. Various reviews noted that the film was shown in the 65mm Vitascope process only in theaters capable of showing widescreen prints. The Var review noted that the print shown at the film's New Orlean's opening was 35mm.

The American Film Institute is grateful to Sir Paul Getty KBE and the Sir Paul Getty KBE Estate for their dedication to the art of the moving image and their support for the AFI Catalog of Feature Films and without whose support AFI would not have been able to achieve this historical landmark in this epic scholarly endeavor.